1. Field of the Invention
This invention relates to diagnosis of electric ignition type engines.
2. Description of the Prior Art
Heretofore, there has been proposed an engine scope for use in inspection of an electric ignition type engine wherein voltage waves appearing across the segments of the distributer of the engine and voltage waves appearing at the secondary side of the ignition coil are displayed, whereby one can determine what are the conditions of the ignition system of the engine and the pressure and the conditions of mixture gas in the combustion chamber of the engine. However, such engine scopes permit only very skillful workers to accurately determine the conditions of the combustion chamber of an engine for the following reasons. Since electric discharge in the spark plug continues only for a time which is as short as one thousandth of a second, the amount of information obtainable from such electric discharge is very much limited. Furthermore, the electric discharge tends to be influenced by changes in the concentration and the pressure of mixture gas in the space between the electrodes of the spark plug.
There has been also proposed a method of determining the conditions of the combustion chamber of an engine by using a strain gauge, a piezo-electric element, or the like. However, such conventional method requires a number of cumbersome preparatory workings such as replacing of plugs and machining of cylinder head.
It is an object of this invention to eliminate the drawbacks of the conventional device and method and to provide a method of and an apparatus for inspecting an electric ignition type engine and capable of accurately and easily determining the pressure in the cylinder of the engine, the conditions of mixture gas such as the concentration and the condition of eddy flow of the mixture gas, and the operating condition of the exhaust valve.